Devices And Method For Positioning Dried Reagent In Microfluidic Devices

Abstract

A microfluidic device may include a sample distribution network including a plurality of sample chambers configured to be loaded with biological sample for biological testing of the biological sample while in the sample chambers, the biological sample having a meniscus that moves within the sample chambers during loading. The sample distribution network may further include a plurality of inlet channels, each inlet channel being in flow communication with and configured to flow biological sample to a respective sample chamber, and a plurality of outlet channels, each outlet channel being in flow communication and configured to flow biological sample from a respective sample chamber. At least some of the sample chambers may include a physical modification configured to control the movement of the meniscus so as to control bubble formation within the at least some sample chambers. At least some of the sample chambers may include a dried reagent positioned within the at least some sample chambers proximate the inlet channels in flow communication with the at least some sample chambers.

1 . A microfluidic device, comprising:
 a sample distribution network comprising:
 a plurality of sample chambers configured to be loaded with biological sample for biological testing of the biological sample while in the sample chambers, 
 a plurality of inlet channels, each inlet channel being in flow communication with and configured to flow biological sample to a respective sample chamber, and 
 a plurality of outlet channels, each outlet channel being in flow communication with and configured to flow biological sample from a respective sample chamber, 
 wherein at least some of the sample chambers comprise a dried reagent disposed within the at least some sample chambers proximate the inlet channels in flow communication with the at least some sample chambers. 
   
     
     
         2 . The device of  claim 1 , wherein the dried reagent is positioned within the at least some sample chambers so as to control bubble formation within the at least some sample chambers. 
     
     
         3 . The device of  claim 2 , wherein the at least some sample chambers are configured to control the position of the dried reagent proximate the inlet channels. 
     
     
         4 . The device of  claim 1 , wherein the dried reagent is positioned in the at least some sample chambers such that a surface defined by the dried reagent and facing substantially toward a center of the at least some chambers extends substantially perpendicular to a longitudinal axis of the outlet channels in flow communication with the at least some sample chambers. 
     
     
         5 . The device of  claim 1 , wherein the dried reagent increases the hydrophilicity of a portion of the at least some sample chambers on which the dried reagent is positioned in comparison to another portion of the at least some sample chambers. 
     
     
         6 . The device of  claim 1 , wherein a pitch between locations of dried reagent in adjacent sample chambers is substantially the same. 
     
     
         7 . The device of  claim 1 , wherein the at least some sample chambers are configured to control a position of the dried reagent within the at least some sample chambers. 
     
     
         8 . The device of  claim 7 , wherein the at least some sample chambers comprise one of a physical modification and a surface modification configured to control the position of the dried reagent within the at least some sample chambers. 
     
     
         9 . The device of  claim 7 , wherein the at least some sample chambers are configured to control the position of the dried reagent such that the dried reagent is not positioned in a region of the at least some chambers between approximately a center of the at least some chambers and the outlet channels in flow communication with the at least some chambers. 
     
     
         10 . The device of  claim 7 , wherein each of the at least some sample chambers comprises one of a protrusion, a groove, a ridge, a region having a greater depth than other regions of each of the at least some sample chambers, a roughened surface portion, and a surface portion having greater hydrophilicity than other surface portions of each of the at least some sample chambers. 
     
     
         11 . The device of  claim 1 , wherein the at least some sample chambers are configured to substantially prevent liquid reagent dispensed in the at least some sample chambers from spreading past a predetermined position as the liquid reagent dries. 
     
     
         12 . The device of  claim 1 , wherein each of the plurality of sample chambers comprises a dried reagent disposed within each sample chamber proximate the inlet channels in flow communication with the at least some sample chambers. 
     
     
         13 . A method of filling a microfluidic device, the method comprising:
 supplying the microfluidic device with a biological sample, the microfluidic device comprising:
 a plurality of sample chambers, 
 a plurality of inlet channels, each inlet channel being in flow communication with and configured to flow biological sample to a respective sample chamber, and 
 a plurality of outlet channels, each outlet channel being in flow communication with and configured to flow biological sample from a respective sample chamber, 
 wherein a dried reagent is positioned within at least some of the sample chambers proximate the inlet channels in flow communication with the at least some sample chambers; and loading the sample chambers with the biological sample. 
   
     
     
         14 . The method of  claim 13 , further comprising controlling bubble formation within the at least some sample chambers via the dried reagent during loading. 
     
     
         15 . The method of  claim 13 , further comprising controlling the position of the dried reagent within the at least some sample chambers. 
     
     
         16 . The method of  claim 15 , wherein controlling the position of the dried reagent comprises controlling the position via one of a physical modification and a surface modification of the at least some sample chambers. 
     
     
         17 . The method of  claim 15 , wherein controlling the position of the dried reagent comprises controlling the position of the dried reagent such that the dried reagent is not positioned in a region of the at least some chambers between approximately a center of the at least some chambers and the outlet channels in flow communication with the at least some chambers. 
     
     
         18 . The method of  claim 15 , wherein controlling the position of the dried reagent comprises controlling the position of the dried reagent via one of a protrusion, a groove, a ridge, a region having a greater depth than other regions of each of the at least some sample chambers, a roughened surface portion, and a surface portion having greater hydrophilicity than other surface portions of each of the at least some sample chambers. 
     
     
         19 . The method of  claim 15 , wherein controlling the position of the dried reagent comprises substantially preventing liquid reagent dispensed in the at least some sample chambers from spreading past a predetermined position as the liquid reagent dries. 
     
     
         20 . The method of  claim 15 , wherein controlling the position of the dried reagent comprises providing a substantially uniform pitch between locations of adjacent sample chambers at which dried reagent is to be positioned.